In a press conference on Friday, Mass. transportation officials announced they ruled out equipment failure in the accident. Transportation Secretary Richard Davey said investigators are focusing on the actions of the moving train's operator. He adds that there is no evidence the operator was carrying their cell phone while on duty.

The Boston Globe reports that the operator, who joined the MBTA in 2006, had been set to receive a safety award Friday. The crash happened about an hour after that driver started their shift.

Davey said the stopped trolley had its lights flashing properly, and its driver was still in the hospital as a precaution.

An MBTA official said shortly after the crash that there was no visible damage to the trains and neither had derailed. He says approximately 35 people reported back and neck pain following the crash and nine others were taken to hospitals. He estimates between 100 and 200 passengers were on board.

Emily Frachtling was in the second car and says it never slowed down before it struck the trolley in front of them.

"We were just going full speed like the same speed that we were going normally," says Frachtling. "The whole time like it didn't slow down at all."

The drivers of both trolleys were placed on paid administrative leave pending an investigation by the MBTA into the crash.